GPNMB and renal cell carcinoma: After inactivation of FLCN, the TFE3 protein can be phosphorylated, and its aggregation in the nucleus is reduced, increasing TFE3 protein transcriptional activity and eventually upregulating the expression of hematopoietic stem cell growth factor-induced neuropeptide (HGFIN), thereby participating in the occurrence of RCC (24).